In a mobile communications device, a Radio Frequency (RF) receive signal may be converted to an equivalent BaseBand (BB) receive signal, and a BB transmit signal may be converted to an equivalent RF transmit signal. The RF is conventionally in the range of several hundred Megahertz (MHz) up to several Gigahertz (GHz) for cellular standards and highly variable due to different frequency bands available in different countries and assigned to different network providers. There may further be frequency division multiple access schemes assigning different frequency resources to different mobile communications devices in a given frequency band.
A Radio Frequency Integrated Circuit (RFIC) may be provided for the BB-RF conversion (and vice versa). The RFIC may include (mainly) analog circuitry and be physically separated (e.g. by means of package) from a (mainly) digital BaseBand Integrated Circuit (BBIC) and an application processor. However, not all analog components of a RF transmit path or a RF receive path may be implementable on the RFIC due to complexity or processing (manufacturing) technology. Moreover, there may be a desire for customization of the RF capabilities. Hence, a plurality of (analog) components (RF front-end components) may be provided separate to the RFIC. For example, one or more antenna switches, duplexers, diplexers, triplexers, frequency filters, Low Noise Amplifiers (LNA), DC-to-DC converters (DCDC) or Power Amplifiers (PA) may be provided separately. Some of these components may be grouped together to more complex front-end modules (e.g. related to supported RF bands).
The RFIC may include one or more Central Processing Units (CPU). The RFIC's CPU may not only control the RFIC internal transmit and/or receive chains. Additionally, the RF front-end components or modules may be configured and controlled by the RFIC. That is, the RFIC may define and control receive and/or transmit paths. For example, an external PA (and its associated DCDC) may be controlled by the RFIC for transmit power control, or an external LNA may be controlled by the RFIC for receive gain control.
The RFIC may allow a clean separation between RF and BB. For example, the BBIC may control the RFIC with an abstract interface, so that the actual implementation of receive and/or transmit paths controlled by the RFIC may be hidden to the BBIC.
With increasing demand on data rate, cellular standards are expanded to transmit and/or receive on multiple frequencies and bands at the same time. For example, support for multi-carrier in the 3G standard of the 3rd Generation Partnership Project (3GPP), carrier aggregation in the 4G standard of the 3GPP, or usage of Multiple Input Multiple Output (MIMO) antennas may be demanded from the mobile communications device. With an increasing number of carriers and an increasing number of antennas per carrier, an increasing number of receive and transmit chains needs to be instantiated in the RFIC. Another factor driving the number of receive and transmit chains may be multi-Subscriber Identity Module (SIM) support. Users demand mobile communications devices supporting more than one SIM, wherein all SIMs are expected to be active in potentially different networks at the same time.
In order to deal with the above requirements, a plurality of transmit and receive chains may be provided (at a same time instant) within the RFIC. However, due to inter-chip frequency coupling or inter-chip interference of different oscillators used for generating different frequencies within the plural receive and transmit chains, only a small number of receive and transmit chains may be implemented on a same die. In order to provide a plurality of transmit and receive paths, a mobile communications device may therefore comprise a plurality of RFICs. For example, the plurality of RFICs and RFIC related resources may be shared between different SIMs.
However, due to the plurality of RFICs, assignment of the various RF front-end components to the RFICs is required. Hence, there may be a desire for intelligent control of a plurality of electronic components arbitrarily assignable to a plurality of integrated circuits of a mobile communications device.